For general photography Kay, it means on a lovely sunny day set it at your cameras lowest iso number, which on your camera (if its the same one) it will most probably be 100, if it gets overcast a bit, you might have to change it to 200 or above, or, if you have an auto iso setting, you can set it to that, and the camera will do everything for you..but again this is for general photograph. The higher settings will make your picture a little more grainier.
:kiss: